Black wavy marks on brass

[stello1001]

Hey all,

This is a first for me. Anyone have any clue how these marks got here? The marks are on the cases after having spent an afternoon dry tumbling in rice. I suppose it's possible they were there prior to going into the tumbler. However, I cannot recall me making that observation before. This is on factory ammo 6.5 grendel.

I also have other cases there from reloads that are tumbling in the same rice simultaneously. These other cases are 6.5 creedmoor and do not show any signs like that.

Any clues?

 

[Edsel]

If it's doughy to borderline sticky, that might be from starch (rice powder) + oil.

 

[Kickin45]

 

[stello1001]

If it's doughy to borderline sticky, that might be from starch (rice powder) + oil.

I think it kinda is. Any reason why it would only stick on the grendel cases? That's pretty weird and a first for me.

 

[Edsel]

I think it kinda is. Any reason why it would only stick on the grendel cases? That's pretty weird and a first for me.

Not sure.

Some powders leave more residue than others, I suppose.

Tulammo .45 ACP residue, for instance, always had this strong Ammonia smell and tended to be hygroscopic.

Just a guess.

But I strongly suspect that gum you have there is a mixture of starch and something else.

 

[stello1001]

Thank you...

I replaced the old rice last night with new one and cleaned the bowl. I'll see here soon if they got cleaned up.

 

[spife7980]

Quicker to take some steel wool to it if it is the gummy stuff

 

[stello1001]

Quicker to take some steel wool to it if it is the gummy stuff

That could've been a good solution too. I swapped out the rice last night and left the brass tumbling. This morning I checked them out and the 4 or 5 pieces that had the black residue now had less. Last night it was very stuck that made removing it with my fingernail tough. This morning, it scratched off real easy.

Thanks everyone for the info. I thought this was very odd and strange but I guess it's happened enough that others knew about it right away haha. I'll add it to the list of things I've now learned from reloading.

 

[straightshooter1]

I think it kinda is. Any reason why it would only stick on the grendel cases? That's pretty weird and a first for me.

I've been using rice for many years and have not seen that on any of my cases, but I might make a guess:

You're rice has been used a lot and is really dirty now; need changing to new rice??? A picture of the rice you used would help with the diagnosis.

Those particular cases have more lube left at the bottom of the grendel cases after sizing, leading to the accumulation of powder residue at that location (in addition to the above)???

 

[stello1001]

I've been using rice for many years and have not seen that on any of my cases, but I might make a guess:

You're rice has been used a lot and is really dirty now; need changing to new rice??? A picture of the rice you used would help with the diagnosis.

Those particular cases have more lube left at the bottom of the grendel cases after sizing, leading to the accumulation of powder residue at that location (in addition to the above)???

The rice is some Asian rice recommended by Greg from primal rights. I got it off Amazon but do not recall exactly which one it is.

The rice was indeed somewhat dirty but not nearly as dirty as I usually let it get before replacing. Never had this issue before with dirtier rice.

None of these cases were lubed. After going over the ziploc bag notes where I had my brass, both (factory grendel cases and factory creed cases) were once fired as factory ammo. I was doing the initial cleaning before sizing so they're still un-prepped other than the tumbling.

The only thing I can think of, the bowl was dirty from many tumbling cycles. Last night I gave it it's first cleaning, actually wiping it with rubbing alcohol. Perhaps all the gunk just happened to accumulate on the grendel cases.

My creed cases are good quality Peterson brass and were already fairly clean. So maybe the gunk couldn't stick to those since the surfaces were clean and smooth. I have no idea, just spit balling haha. My grendel cases are S&B, and while fairly consistent in the SD numbers (for mass produced ammo), they still shoot quite dirty.

 

[CK1.0]

Rice sucks for tumbling IME. Rice leaves a weird film on the cases and gets dirty too fast. Like most stuff Orkan/Greg from Primal Rights says/recommends, it’s not fully vetted and is arguably bad advice and better left ignored IMO.

Get yourself some 20-40 grit corn cob blasting media, it pours out of the cases like water when you’re done and cleans much better.

 

[stello1001]

Rice sucks for tumbling IME. Rice leaves a weird film on the cases and gets dirty too fast. Like most stuff Orkan/Greg from Primal Rights says/recommends, it’s not fully vetted and is arguably bad advice and better left ignored IMO.

Get yourself some 20-40 grit corn cob blasting media, it pours out of the cases like water when you’re done and cleans much better.

I will consider this and shop around for it.

I liked the idea of rice because of the minimal dust it creates. How has corn cob been for you in this regard?

 

[CK1.0]

I will consider this and shop around for it.

I liked the idea of rice because of the minimal dust it creates. How has corn cob been for you in this regard?

Honestly, the corn cob blasting media is pretty dusty; it's sort of "garage only" versus something you'd want in the house... it's fine grit stuff, 20-40 grit blasting media is way finer than most corn cob tumbling media that most of us are familiar with.

That said, it really does work great, but the biggest thing is that instead of having to beat the crap out of the brass after tumbling to get all the media out of the cases with a media separator or whatever, all you have to do is turn them upside down and let the media pour out. I just put on a pair of nitrile gloves and can hold ~10 cases upside down in one hand between my fingers while my other hand picks them up. It only takes ~2 minutes to go through 100 cases.

Since I started doing it this way, not having to beat the crap out of the cases post-tumbling has noticeably shrunk my average SDs, it's pretty nuts how obvious it is, as the difference shows up in the chrono numbers and downrange.

 

[softcock]

I been using Hazelnut tumbling media lately, it super hard and clean . There is online dealers that get it from.
I not adverse to walnut, but there is just and over abundance here in my area with hazelnut because it one of the bigger crops being produced local.
.

 

[memilanuk]

having to beat the crap out of the cases post-tumbling has noticeably shrunk my average SDs

If you're having to 'beat the crap' out of your cases post tumbling with rice, you're doing something wrong - like the wrong grain size of rice. Smaller, shorter grains work better and come out pretty much just like corn/walnut, with a regular rotary media separator. The 'milled' stuff that Primal Rights sells works even better in that regard, but holy f$ck it's pricey. I tried one bag just to see how it worked; afterwards I went down to the local Ace hardware and got a hand-cranked grain mill. Plan is to try milling my own next time from cheap, locally available rice (ie Costco/Walmart/grocery store). Guess we'll see if that works as expected.

Otherwise, yeah, I do agree that corn cob is pretty goof-proof. Just dustier than I care for. But it does get the cases oh-so shiny

 

[CK1.0]

I don’t purposely try to beat the crap out of cases, and doing a mandrel step after the fact helps undo most damage, but even while being careful, those rotary media separators are rougher on cases and particularly case mouths than most think.

With the fine blast-media, I can skip the media separator altogether, and then the roughest thing my brass sees is the dry tumbler.

 

[MarinePMI]

If rice was the most desired media, then I can guarantee you the manufacturers would be using it....but they don't. Probably for good reason.

 

[straightshooter1]

If rice was the most desired media, then I can guarantee you the manufacturers would be using it....but they don't. Probably for good reason.

Hmmm??? "Most desired" depends on the objective and cost.

 

[DeathBeforeDismount]

Its 2025, are people really still dry tumbling? Corn cob, rice, Russian groats........wtf.

Ultrasonic or wet tumbler with no media is faster, cleaner and cheaper.

 

[straightshooter1]

Its 2025, are people really still dry tumbling? Corn cob, rice, Russian groats........wtf.

Ultrasonic or wet tumbler with no media is faster, cleaner and cheaper.

But, I and many other's don't want in inside neck surfaces to be so clean. That residual layer left after firing acts nicely as a lubricant where having an extra step in the process for lubing in necks isn't needed. And in the case of rice, it can actually add additional lubrication.

 

[stello1001]

Its 2025, are people really still dry tumbling? Corn cob, rice, Russian groats........wtf.

Ultrasonic or wet tumbler with no media is faster, cleaner and cheaper.

Yes it's 2025 and us savages are still dry tumbling. Did it make your groups open up? No right, didn't think so lol.

 

[stello1001]

But, I and many other's don't want in inside neck surfaces to be so clean. That residual layer left after firing acts nicely as a lubricant where having an extra step in the process for lubing in necks isn't needed. And in the case of rice, it can actually add additional lubrication.

That's why I haven't considered wet tumbling. I get pretty good groups and chrono numbers dry tumbling that I haven't found myself thinking about wet tumbling.

 

[hlee]

If dust is a problem, just run the tumbler outside (not in a garage, outside outside), with the lid off.

 

[CK1.0]

Wet tumbling precision cases = bad (I don’t care how shiny they come out lol). Wet-tumbling is for blaster ammo only.

One can literally see the difference between wet-tumbling vs dry-tumbling on their chronograph (the dry stuff will be the strings with the lower SD/ES numbers).

I use the ultrasonic cleaner for what it’s best at and what I got it for: muzzle brakes.

 

[stello1001]

Thank you all who contributed. I no longer care for any replies that include how one way of tumbling is better than another. Everyone's way is always going to be the best is what I've gathered.

My issue had resolved and I have learned from it!

 

[vh20]

I don’t purposely try to beat the crap out of cases, and doing a mandrel step after the fact helps undo most damage, but even while being careful, those rotary media separators are rougher on cases and particularly case mouths than most think.

With the fine blast-media, I can skip the media separator altogether, and then the roughest thing my brass sees is the dry tumbler.

Especially when dealing with the Lapua/Norma Magnum cartridges, the cases are so heavy that the thought of running them through a rotary separator makes me cringe. Even the slightest drop always results in a case-mouth dent.

 

[DeathBeforeDismount]

But, I and many other's don't want in inside neck surfaces to be so clean. That residual layer left after firing acts nicely as a lubricant where having an extra step in the process for lubing in necks isn't needed. And in the case of rice, it can actually add additional lubrication.

You still have carbon left in necks after wet tumbling.....

 

[DeathBeforeDismount]

Yes it's 2025 and us savages are still dry tumbling. Did it make your groups open up? No right, didn't think so lol.

Yea I only spend about 30k a year traveling to shoot matches where precision is paramount to throw it all away by wet tumbling......use your brain.

There is zero difference in sd/es between methods... Unless you count stuck media and other shit in your cases effecting internal ballistics.

Pure ignorance.

 

[stello1001]

Yea I only spend about 30k a year traveling to shoot matches where precision is paramount to throw it all away by wet tumbling......use your brain.

There is zero difference in sd/es between methods... Unless you count stuck media and other shit in your cases effecting internal ballistics.

Pure ignorance.

Wow, I'm so impressed.

 

[straightshooter1]

You still have carbon left in necks after wet tumbling.....

View attachment 8742079

Wet tumbling without media does leave some of that carbon in the neck. But usually not enough is left for decent lubrication. Whenever I wet tumble, which is on rare occasions, that's how I do it when I've got a bunch of brass that's got a bunch of dirt, mud and grim inside, then I'll wet tumble to be sure the interior is cleaned out. But wet tumbling adds more time to processing, having to go through the effort for rinsing and drying them out. While with dry tumbling, there is that time getting the media out of the case, but that time is way less than that for wet tumbling.

Nothing wrong with taking the extra time that wet tumbling requires and the time for lubing the necks also. It's all really just a matter of preference anyway. But it's nice to know what's involved with any of the choices to make an informed decision.

 

[CK1.0]

While keeping some carbon inside the necks is a big deal, what I don’t like about wet tumbling is all the variability having the cases crash into each other violently adds to the process.

Whether with SS pins or without, if you look through the little side windows while a wet tumbler is going it’s easy to see that the cases are getting the crap kicked out of them while they get bashed around against each other in the water… which definitely has something to do with why the batches never really come out the same time after time.

To me, reloading is mostly about repeatability, and with dry tumbling I can get the same results batch after batch, allowing me to keep my SDs around the same batch after batch. When I was still wet tumbling, my shit would be all over the place batch to batch with worse average numbers showing up on the chrono, always.

 

[jthor]

Its 2025, are people really still dry tumbling? Corn cob, rice, Russian groats........wtf.

Ultrasonic or wet tumbler with no media is faster, cleaner and cheaper.

I stopped wet tumbling almost 4 years ago and switched to dry tumbling in rice and I’ll never go back.

There was a huge difference in how smooth my bullets were seating in my dry tumbled brass with rice vs my wet tumbled brass. It’s also hardly faster or less work than dry tumbling when all is said and done with having to dry the brass.

I also got more consistent numbers when I switched. From my fresh ammo to old.

Shooters in F Class, who need more precision, tend to dry tumble. There’s probably a reason for it.

 

[jthor]

Thank you...

I replaced the old rice last night with new one and cleaned the bowl. I'll see here soon if they got cleaned up.

Cut a drier sheet into 4 pieces. It will help keep the media cleaner for longer. Also, don’t neglect cleaning your dry tumbler out with IPA. That will help prevent that gunk from building up also.

 

[MarinePMI]

Wet tumbling precision cases = bad (I don’t care how shiny they come out lol). Wet-tumbling is for blaster ammo only.

One can literally see the difference between wet-tumbling vs dry-tumbling on their chronograph (the dry stuff will be the strings with the lower SD/ES numbers).

I use the ultrasonic cleaner for what it’s best at and what I got it for: muzzle brakes.

The trick for wet tumbling precision cases is to not tumble with pins. Cleans the cases without peening the necks. Also only takes about 30 mins.

 

[straightshooter1]

The trick for wet tumbling precision cases is to not tumble with pins. Cleans the cases without peening the necks. Also only takes about 30 mins.

That's been my experience too, where 30 mins or less without pins (particularly in hot water) cleans cases up nicely. I don't know why some think they have to go for hours. In an experiment, I found not much tumbling has to be done at all. Just soaking the cases in the hot water solution pretty much does the trick. I took a small bucket with hot water and the Dawn and Lemi Shine solution and let a batch of brass soak for 1/2 hr and before removing the brass, I agitated the brass with my hand a few times as I rinsed the brass off in running water to remove the solution. They turned out just as good as those tumbled for 1/2 hr. Apparently, its that hot water solution that does almost all the work.

 

[DeathBeforeDismount]

The trick for wet tumbling precision cases is to not tumble with pins. Cleans the cases without peening the necks. Also only takes about 30 mins.

Exactly. I do about 15-20 mins post anealing so cases go through Dillion/sizer clean and then 15-20 post sizing to get lube off. Cases are clean but still carbon inside them to act as lube and prevent galling.

Not only do you prevent peening but you don't have to media separate. Much faster and easier...and no risk of steel pins getting stuck in a case and shot down your bore.

 

[Maurygold]

Left is dry media. Right is ultrasonic.

These are 9 firings in. I’ve been super happy with the dry tumbler method lately

 

[DeathBeforeDismount]

That's been my experience too, where 30 mins or less without pins (particularly in hot water) cleans cases up nicely. I don't know why some think they have to go for hours. In an experiment, I found not much tumbling has to be done at all. Just soaking the cases in the hot water solution pretty much does the trick. I took a small bucket with hot water and the Dawn and Lemi Shine solution and let a batch of brass soak for 1/2 hr and before removing the brass, I agitated the brass with my hand a few times as I rinsed the brass off in running water to remove the solution. They turned out just as good as those tumbled for 1/2 hr. Apparently, its that hot water solution that does almost all the work.

Add a few oz of brass cleaner from boretech to lemishine/dawn and it really cleans the cases well.

 

[DeathBeforeDismount]

Left is dry media. Right is ultrasonic.

These are 9 firings in. I’ve been super happy with the dry tumbler method lately

View attachment 8742316

It's not a beauty contest. You don't need shiney polished brass. In fact, you want some roughing to keep from getting chamber stick and premature case head separation. It's why chambers shouldn't be a mirror finish.

If you rinse the wet tumble a couple times...it comes out much cleaner with less residue. I doubt you will see any difference in performance down range.

 

[Baron23]

I dry tumble in walnut media....in my garage...but I really don't see any issue with dust/debris and my cases come out fine for my purposes.

 

[Maurygold]

It's not a beauty contest. You don't need shiney polished brass. In fact, you want some roughing to keep from getting chamber stick and premature case head separation. It's why chambers shouldn't be a mirror finish.

If you rinse the wet tumble a couple times...it comes out much cleaner with less residue. I doubt you will see any difference in performance down range.

I find the dry media to be substantially easier to use as well as better at cleaning. I am seeing zero extraction or negative effects from it. Plus there is no cooking brass or drying off time.